Genus Pachydellus Mašán, 2007

Pachydellus Mašán, 2007a: 161 .

Type species Pachylaelaps sculptus Berlese, 1920, by original designation.

Mašán (2007a) erected the genus Pachydellus to accommodate species that share the following character states: (1) clunal setae J5 minute, reduced to minute microsetae; (2) spermathecal tube of sperm access system strongly reduced to very short section mostly fully concealed inside the posterior margin of coxa III (Fig. 2); (3) slit-like opening of glands gdZ1 placed in alignment with setae Z1-Z2; (4) female tarsus II with one spur-like seta; (5) genu I with 12 setae; (6) male femur II always with axillary tubercle close to a large anterolateral distal projection; (7) male chelicera with spermatodactyl foliate, widened basally, curved medially and narrowed distally.

Pachydellus is distributed exclusively throughout the Palaearctic region, except that Pachydellus hades may have been introduced into Australia by human activities ( Halliday, 2001). It currently comprises 14 valid species from Europe and Asia, but we suspect that several of these species may include a complex of sibling species.